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G7 on a Post-it Note

A guide to getting repeatable color matches on press, everyday

The G7 methodology has been critisized as being 'too complicated'.

It is not.

Here is a very nice summary of the process that was orignially published by Glenn Andrews of Schawk in Los Angeles. (with a couple of small changes of mine).

1. Use good paper and good ink.

2. Have the press in good running condition.3. Include color bars with solids, overprints, a 50%C 40%M 40%Y neutral and a 50% or 53% midtone K patch.4. Run to industry-standard solid ink densities.5. Mid-tone density must be 0.54 plus the density of the paper.6. 50%C 40%M 40%Y neutral must be exactly the same color and value as the mid-tone K.

A press sheet run to these specificationswill match a good proof.

Thursday, September 25, 2008

Some things don't change...

In my files, I recently found this proofing bar that was developed by Felix Brunner for the DuPont's Cromalin proofing system. The copyright date is 1983, so I'm guessing that the printed image is from sometime in the mid to late 80s. Brunner created some unique test elements to help manage color reproduction in proofs and press sheets. I will talk about those a little later. Seeing this 'ancient' bar reminded me of something I had learned earlier this year that I thought was very interesting:

A few months ago, I was assisting a SystemBrunner instructor in demonstrating process control strategies for Instrument Flight. To illustrate his points, he used an image that was printed by Felix Brunner many decades ago. The picture was accompanied by a color bar very similar to the one pictured above.

I happened to have a spectrodensitometer at hand and was curious about the density of the 3-color and black gray patches. While the technique of monitoring the midtone density value was not part of the Brunner control strategy, it IS defined as an important target in the new G7 methodology.

I was somewhat startled to find that in measuring the midtone (50/41/41) patch of this 20 year-old color bar, the density was, in fact, 0.54 above paper: precisely the same target density prescribed by G7 as the 50/40/40 midtone value on the Neutral Print Density Curve (NPDC).

So, it appears that the same elements of good printing haven't changed. In order of priority: balance, tone, and color.

To my mind, this very early Brunner work validates the much-maligned G7 method. G7 seems to have embraced and refined the early work of research pioneers, adapting these ideas for today's electronics-dominated printing industry. Film-positive originals were the image source in Brunner's day. G7 depends heavily on the flexibility and precision of the modern CtP plate-making systems, spectros, RIPS and .pdf source files. But, the process techniques and tools that Brunner developed many years ago, and the G7 methods of today, have the same ultimate objective: to reproduce high-quality color images on paper.

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What is a G7® Expert Consultant

GRACoL Expert Consultants are industry trainers and consultants who have completed an IDEAlliance certification program and are identified to be an elite group of professionals who are expert in the new GRACoL press calibration process.

What is a G7 Master?

The IDEAlliance G7 Master Program is a qualification program that identifies those creatives, premedia and printing companies who have been trained to proof or print to G7 Neutral Print Density Curves and can meet print buyer requirements to produce proofs or printed output conforming to the metrics that reliably render brand images across print locations and different printing types.. The qualification mark means that the printer uses the modern technology based on colorimetry, and employ G7 process controls. G7 Masters bear the IDEAlliance seal of approval. Attaining G7 Master status is a competitive goal for those providing creative, premedia and printing services, worldwide.

How Can G7 Experts Help My Company to Become a G7 Master?

To become a G7 Master your shop must be qualified by an IDEAlliance G7 Expert Consultant. These are color management professionals who have been trained in hands-on sessions and are certified by IDEAlliance to teach G7 techniques. G7 Expert Consultants are uniquely qualified to train printers, creatives and prepress houses in the G7 Method and are authorized to act as the qualification agents for IDEAlliance G7 Masters. Each G7 Expert consultant has their own consulting practice and determines their own pricing and engagement methodology.